1. Field of the Invention
The present invention relates to portable expanding envelopes that are utilized to organize papers into different sections between divider panels.
2. Description of the Prior Art
In the past, various office supply filing envelopes have been devised for the purpose of organizing papers within a portable filing envelope. Conventional devices of this type are typically constructed with a front cover panel, a rear cover panel, and a bottom or spine panel located therebetween. The sides of the front and rear covers are typically joined together by side panels, which often employ one or more folds extending from bottom to top so that the side panels are collapsible. One or more divider panels may be located within the envelope so formed in order to organize the contents of the envelope into different compartmentalized sections. The side edges of the divider sheet or sheets are often attached to the side panels of the envelope, but are frequently left unattached to the bottom or spine panel.
In conventional filing envelopes of this type, papers stored in the envelope will frequently slip down beneath the lower edges of the when the envelope is transported or used. When this occurs the user is often frustrated in attempting to locate specific papers, since they appear not to be within the file section in which they had been placed. In addition, when papers slip partially beneath the lower edges of the divider sections, they often become wrinkled and crumpled. Important papers can become damaged in this way.
A primary object of the present invention is to provide a portable expanding envelope with built-in dividers which is easy to construct and which provides a barrier to papers slipping beneath the divider panels. Unlike conventional portable, expanding file folders, the envelope of the present invention provides a safeguard against papers slipping beneath the file section dividers and becoming difficult to find, crumpled, and damaged.
A further object of the present invention is to provide an improved filing envelope system in which an envelope can be constructed with internal divides very easily and quite economically.
Still another object of the invention is to provide a portable filing envelope with built-in dividers that may be utilized to reliably sort papers into different sections between the divider panels and between the front and rear panels of the envelope.
In one broad aspect the present invention may be considered to be an expanding envelope with built-in dividers comprising: an expansive base sheet formed of a resilient, stiff material, and an expansive divider sheet formed of a resilient, stiff material. The base sheet is delineated into a front cover panel, a rear cover panel, and collapsible side panels on opposite sides of the front and rear cover panels. The base sheet also includes a narrow spine panel located between the front and rear cover panels. The spine panel is delineated from the front and rear cover panels by a pair of base sheet bottom folds. The spine panel is divided transversely by a center fold into front and rear collapsible sections. The divider sheet is delineated into front and rear divider panels and a binder panel located between the front and rear divider panels. The binder panel is also divided transversely by a center fold into front and rear collapsible sections. The front and rear collapsible sections of the divider panel are respectively secured to the front and rear collapsible sections of the spine panel.
The side panels are both divided by center folds at which they are collapsible. The collapsible side panels secure the front and rear cover panels to each other with the front and rear divider panels located therebetween. The collapsible side panels are provided with bifurcating center folds that extend substantially parallel to the front and read cover panels.
To fabricate the expanding envelope of the present invention the divider sheet is laid atop the base sheet. The two sheets are then secured together, preferably by mutually parallel lines of heat sealing that are located on opposite sides of the transverse, center fold in the spine panel.
Both the base sheet and the divider sheet are then counterfolded, on both sides of the center fold in the spine panel in a direction opposite the spine panel center fold so as to delineate the front and rear cover panels on the base sheet and front and rear divider panels on the divider sheet. The side panels are formed as lateral extensions of the base sheet from either the front or the rear cover panel. The side panels are then folded from the cover panel from which they extend toward the opposite cover panel, and are secured thereto, preferably by further lines of heat sealing.
By fastening the base sheet and divider sheet together at the bottom of the envelope structure, pockets are created between the divider panels and the front and rear cover panels. These pockets are closed at the bottom of the envelope. Papers can therefore not slip down beneath the divider panels, as occurs in some conventional expanding envelopes.
In another broad aspect the invention may be considered to be an expanding envelope with built-in dividers comprising an expansive base sheet and an expansive divider sheet, both formed of a resilient, stiff material. Both the base sheet and the divider sheet are preferably formed of a resilient, economical plastic, such as polypropylene or polyethylene.
The base sheet is folded transversely to form a base sheet center fold and is counterfolded transversely on both sides of the base sheet center fold to form a pair of base sheet bottom folds parallel to and spaced from the base sheet center fold. This construction allows the base sheet to be collapsible at the base sheet center fold and also delineates front and rear envelope panels from the base sheet. These front and rear envelope panels project upwardly from the base sheet bottom folds.
The base sheet further defines laterally projecting side panels that extend between and permanently secure the front and rear envelope panels together in mutually facing relationship. The side panels are folded inwardly toward each other and are doubled back to delineate bifurcating side panel folds perpendicular to the base sheet center fold. In this way the side panels are collapsible at the center side panel folds.
The divider sheet is folded transversely to form a divider sheet center fold parallel to and in registration with the base sheet center fold. The divider sheet is also counterfolded to form divider sheet bottom folds parallel to and spaced from the divider sheet center fold. This construction delineates front and rear divider panels located between and respectively facing the front and rear envelope panels. The divider sheet center fold lies adjacent and parallel to the base sheet center fold. This allows the divider sheet to be collapsible with the base sheet at the divider sheet center fold.
The base sheet and the divider sheet are permanently secured together between their center folds and their bottom folds. Preferably, both the base sheet and divider sheet are formed of sheets of plastic and are secured to each other between their center folds and the bottom folds by mutually parallel straight sealing lines that lie on opposite sides of the center folds. The lines of sealing are preferably formed by heat sealing the two sheets together.
In another broad aspect the invention may be considered to be a method of fabricating expandable envelopes with built-in dividers. The method of the invention utilizes an expansive base sheet having opposing side panels and an expansive divider sheet. Both the base sheet and the divider sheet are formed of a resilient, stiff material.
According to the method the divider sheet is positioned atop the base sheet in contact therewith. The fabricator then permanently secures the divider sheet and the base sheet together along a pair of mutually parallel, transverse front and rear lines of attachment. The base sheet and divider sheet are then folded upwardly together parallel to and between the transverse lines of attachment to create transverse, collapsible center folds therein. The sheets are then counterfolded together in both front and rear, mutually parallel transverse bottom folds so that the front line of attachment resides between the center folds and the front bottom folds and so that the rear line of attachment resides between the center folds and the rear bottom folds. This creates from the base sheet front and rear cover panels, each having a top and a bottom. It also creates from the divider sheet a pair of divider panels between the front and rear cover panels. The side panels project outwardly from a first one of the front and rear cover panels.
Both of the side panels of the base sheet are then folded toward each other to span the distance of separation between the front and rear cover panels. Each of the side panels is also folded longitudinally back upon itself so as to form a longitudinal, bifurcating fold in each of the side panels. The side panels are permanently secured to a second one of the front and rear cover panels longitudinally from the top to the bottom thereof.
Preferably, both the base sheet and the divider sheet are formed of plastic, such as polyethylene or polypropylene, and the lines of attachment of these sheets together is preferably formed by heat sealing.
Preferably also, the base sheet is further comprised of bottom attachment tongues projecting from the side panels. The bottom attachment tongues are directed toward each other and are sealed to the divider sheet between the front and rear folds therein. The bottom attachment tongues are also preferably sealed to the spine panel formed from the base sheet.
The invention may be described with greater clarity and particularity by reference to the accompanying drawings.